Method of providing 911 service to a private branch exchange

ABSTRACT

A method of providing 911 service to a private branch exchange, includes grouping a plurality of private telephone numbers into a set. An outgoing telephone line for a 911 call is assigned to the set. A location information for the outgoing telephone line is input into a location database.

FIELD OF THE INVENTION

The present invention relates to generally to the field of 911 emergencyservice systems and more particularly to a method of providing 911service to a private branch exchange.

BACKGROUND OF THE INVENTION

A Public Safety Answering Point (PSAP) uses an automatic locationidentification (ALI) information provided with the automatic numberidentification (ANI) to determine the location of a 911 telephone call.Unfortunately, when a 911 call is placed from a business having a PBX(Private Branch Exchange), the PSAP only receives the billing address ofthe business. For large businesses having multiple locations, this doesnot provide any useful information. Some PBX providers allow the ownersto enter in correct location information for all their lines.Unfortunately, this is time consuming and therefor rarely is done.

Thus there exists a need for a method of providing 911 service to aprivate telephone numbering system that is easy to setup.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram of public safety answering service for aprivate telephone numbering system in accordance with one embodiment ofthe invention.

FIG. 2 is a flow chart of the steps used in a method of providing 911service to a private branch exchange in accordance with one embodimentof the invention;

FIG. 3 is a flow chart of the steps used in a method of providing 911service to a private branch exchange in accordance with one embodimentof the invention; and

FIGS. 4 & 5 are a flow chart of the steps used in a method of providing911 service to a private branch exchange in accordance with oneembodiment of the invention.

DETAILED DESCRIPTION OF THE DRAWINGS

A method of providing 911 service to a private branch exchange, includesgrouping a plurality of private telephone numbers into a set. Anoutgoing telephone line for a 911 call is assigned to the set. Alocation information for the outgoing telephone line is input into alocation database (E911 database). By grouping the telephone linessignificantly less information has to be input into the locationdatabase. The groups are selected to be telephone lines in a setgeographic area. For instance all the telephones on the third floor of asmall building might be grouped together. This provides emergencypersonnel with plenty of information to locate the emergency.

FIG. 1 is a block diagram of public safety answering service for aprivate branch exchange in accordance with one embodiment of theinvention. A public safety answering point (PSAP) 10 includes a switch12 connected to a SSP (Service Switching Point) 14. The switch 12triggers on incoming call and forms a location query. The location queryis set to a location database (E911 database) 16. The call and locationinformation are forwarded to one of a plurality of operators 18.

A company 20 using a PBX 22 groups private telephone lines according totheir location. This company 20 has two locations 24, 26. Any 911 callfrom the first location 24 is routed over a predetermined publictelephone line 28. Any 911 call from the second location 26 is routedover a predetermined public telephone line 30. The PBX is connected to aSSP 32. A 911 call is then sent to SSP 14 and to the PSAP 10. A SCP(Service Control Point) 34 is connected through an intelligent networkto the SSPs 14, 32. The SCP 34 may provide routing information to theSSP 32 for 911 calls. A second company 36 also has a PBX 38. The company36 also divides its telephones into two locations 38, 40. Note that anynumber of locations could be handled and the invention encompasses morethan a single PBX, A 911 call from any of the telephones in the firstlocation 38 are routed over a predetermined external telephone line 42.A 911 call from any of the telephones in the second location 40 arerouted over a predetermined external telephone line 44.

FIG. 2 is a flow chart of the steps used in a method of providing 911service to a private branch exchange in accordance with one embodimentof the invention. The process start, step 60, by grouping a plurality oftelephone numbers into a set at step 62. An outgoing telephone line fora 911 call is assigned to the set at step 64. At step 66, a locationinformation for the outgoing telephone line is input into a locationdatabase of a telephone company which ends the process at step 68. Inone embodiment, the plurality of private telephone numbers are selectedby an origination location. In one embodiment a private branch exchangeis programmed to selected the outgoing telephone line when a 911 call isreceived from one of the plurality of private telephone numbers.

In one embodiment when the 911 call is dialed from one of the pluralityof private telephone numbers, the 911 call is sent out over the outgoingtelephone line. The 911 call is triggered on at a service switchingpoint. A routing, query is transmitted to a switching control point(SCP). A routine instruction is received from the SCP. The 911 call isrouted to a proper PSAP. A location database is queried for a locationassociated with a telephone number of the outgoing telephone line.

FIG. 3 is a flow chart of the steps used in a method of providing 911service to a private branch exchange in accordance with one embodimentof the invention. The process starts, step 80, by receiving a 911 callat a private switch at step 82. In one embodiment, the private switch isa private branch exchange. A dialing telephone number is determined atstep 84. An associated outgoing telephone line is looked up at step 86.At step 88, the 911 call is placed over the associated outgoingtelephone line which ends the process at step 90. The 911 call isreceived at a service switching point (SSP). The 911 call is triggeredon and the SSP sends a query to a switching control point (SCP). Aresponse is received that includes a routine instruction. In oneembodiment the response includes the number of the associated outgoingtelephone line. The 911 call is routed to a public safety answeringpoint (PSAP). A location query is sent to a location database. The 911call is forwarded to an operator. A location information is transmittedto the operator.

In one embodiment, a first plurality of private telephone numbers aregrouped into a first set. A second plurality of private telephonenumbers are grouped into a second set. One of a plurality of outgoingtelephone lines is assigned to the first set. A second of the pluralityof outgoing telephone lines is assigned to the second set. The locationdatabase is programmed to include a location for the one of theplurality of outgoing telephone lines and a second location for thesecond of the plurality of outgoing telephone lines.

FIGS. 4 & 5 are a flow chart of the steps used in a method of providing911 service to a private branch exchange in accordance with oneembodiment of the invention. The process starts, step 100, by grouping afirst plurality of private telephone numbers into a first set at step102. A second plurality of private telephone numbers is grouped into asecond set at step 104. One of a plurality of outgoing telephone linesis assigned to the first set at step 106. A second of the plurality ofoutgoing telephone lines is assigned to the second set at step 108. Alocation database is programmed to include a location for the one of theplurality of outgoing telephone lines at step 110. The location databaseis programmed to include a second location for the second of theplurality of outgoing telephone lines at step 112. A 911 call isreceived at a private switch at step 114. A dialing telephone lumber isdetermined at step 116. At step 118 it is determined if the dialingtelephone number belongs in the first set or the second set. When thedialing telephone number belongs in the first set at step 120, the 911call is place over the one of the plurality of outgoing telephone lineswhich ends the process at step 122. When the dialing telephone numberbelongs in the second set, the 911 call is place over the second or theplurality of outgoing telephone lines. The 911 call is received at aservice switch point. The 911 call is triggered on and a query is sentto a switching control point. A response is received that includes arouting instruction. The 911 call is routed to a public safety answeringpoint. A location query is gent to the location database. The all isforwarded to an operator. A location information is transmitted to theoperator.

Thus there has been described a method of providing 911 service to aprivate telephone numbering system that is easy to setup.

The methods described herein can be implemented as computer-readableinstructions stored on a computer-readable storage medium that whenexecuted by a computer will perform the methods described herein.

While the invention has been described in conjunction with specificembodiments thereof, it is evident that many alterations, modifications,and variations will he apparent to those skilled in the art in light ofthe foregoing description. Accordingly, it is intended to embrace allsuch alterations, modifications, and variations in the appended claims.

What is claimed is:
 1. A method of providing 911 service to a privatebranch exchanger comprising the steps of: a) groupings a plurality ofprivate telephone numbers into a set; b) assigning an outgoing telephoneline for a 911 call to the set; and c) inputting a location informationfor the outgoing telephone line in a location database.
 2. The method ofclaim 1, wherein step (a) further includes the step of: a1) selectingthe plurality of private telephone numbers by an origination location.3. The method of claim 1, wherein step (b) further includes the step of:b1) programming a private branch exchange to select the outgoingtelephone line, when the 911 call is received from one of the pluralityof private telephone numbers.
 4. The method of claim 1, furtherincluding he step of: d) when the 911 call is dialed from one of theplurality of private telephone numbers, sending the 911 call out overthe outgoing telephone line.
 5. The method of claim 4, further includingthe steps of: e) triggering on the 911 call at a service switch point;f) transmitting a routing query to a switching control point; g)receiving a routing instruction from the switching control point.
 6. Themethod of claim 5, further including the steps of: h) routing the 911call to a public safety answering point; i) querying a location databasefor a location associated with a telephone number of the outgoingtelephone line.
 7. A method of providing 911 service to a private branchexchange, comprising the steps of: a) receiving a 911 call at a privateswitch; b) determining a dialing telephone number; c) looking up anassociated outgoing telephone line; and d) placing the 911 call over theassociated outgoing telephone line.
 8. The method of claim 7, whereinstep (a) further includes the step of: a1) receiving the 911 call at aprivate branch exchange.
 9. The method of claim 7, further including thesteps of: e) receiving the 911 call at a service switching point; f)triggering on the 911 call and sending a query to a switching controlpoint; g) receiving a response including a routing instruction.
 10. Themethod of claim 9, wherein step (g) further includes the step of: g1)receiving the response including a number of the associated outgoingtelephone line.
 11. The method of claim 9, further including the stepsof: h) routine the 911 call to a public safety answering point; i)sending a location query to a location database.
 12. The method of claim11, further including the steps of: j) forwarding the 911 call to anoperator; k) transmitting a location information to the operator. 13.The method of claim 7, wherein step (a) further includes the steps of:a1) grouping a first plurality of private telephone numbers into a firstset; a2) grouping a second plurality of private telephone numbers into asecond set; a3) assigning one of a plurality of outgoing telephone linesto the first set; a4) assigning a second of the plurality of outgoingtelephone lines to the second set.
 14. The method of claim 13, furtherincluding the step of: a5) programming a location database to include alocation for the one of the plurality of outgoing telephone lines. 15.The method of claim 14, further including the steps of: a6) programmingthe location database to include a second location for the second of theplurality of outgoing telephone lines.
 16. A method of providing 911service to a private branch exchange, comprising the steps of: a)grouping a first plurality of private telephone numbers into a firstset; b) grouping a second plurality of private telephone numbers into asecond set; c) assigning one of a plurality of outgoing telephone linesto the first set; d) assigning a second of the plurality of outgoingtelephonic lines to the second set, e) programming a location databaseto include a location for the one of the plurality of outgoing telephonelines; f) programming the location database to include a second locationfor the second of the plurality of outgoing telephone lines; g)receiving a 911 call at a private switch; h) determining a dialingtelephone number; i) determining if the dialing telephone number belongsin the first set or the second set; and j) when the dialing telephonenumber belongs in the first set, placing the 911 call over the one ofthe plurality of outgoing telephone lines.
 17. The method of claim 16,further including the step of: k) when the dialing telephone numberbelongs in the second set, placing the 911 call over the second of theplurality of outgoing telephone lines.
 18. The method of claim 16,further including the steps of: k) receiving the 911 call at a serviceswitching point; l) triggering on the 911 call and sending a query to aswitching control point; m) receiving a response including a routinginstruction. h) routing the 911 call to a public safety answering point;i) sending a location query to the location database j) forwarding thecall to an operator; and k) transmitting a location information to theoperator.